FAQ

What are composite materials?

A composite material is one which is composed of at least two elements working together to produce material properties that are different to the properties of those elements on their own. Thus, concrete reinforced with steel is a composite, but in this context, we are only interested in polymer composites; sometimes referred to as GRP – glass reinforced polymer, or plastic or FRP – fibre reinforced polymer.

In practice, polymer composites consist of a resin and a reinforcement of some kind. This reinforcement is usually in fibre form, typically glass fibres, carbon fibres, aramid (e.g. Kevlar) or sometimes natural fibres such as flax. The most common resins used are polyester, epoxy, phenolic and vinylester, although natural resins such as Furan are also becoming available as demand increases. At PE Composites, we often use less common materials combinations in order to achieve very specific properties of the particular component such as Radio Frequency (RF) transparency and reaction to fire.

PEC has the ability to almost infinitely alter the constituent parts of the composite, and change the way in which it is processed, allowing the properties of the cured composite material to be tailored in ways that other materials cannot.

What certifications does PE Composites have?

PE Composites are accredited to BS EN ISO 9001:2015 and to Cyber Essentials

Can you ship to my country?

Almost certainly we can – virtually every week PEC are shipping something to somewhere in the world. This is, of course, all subject to any particular UK Government regulations in force at the time where the export of certain products to certain countries may be restricted.

Where do you manufacture?

Everything is manufactured in our facilities located in Newport on the Isle of Wight, an island situated close to the south coast of England. Nearest ports are Southampton and Portsmouth. Numerous car ferries and fast ferries for foot passengers operate all year round.

How long is a composite structure likely to last?

This is a simple question that demands a complex answer as it depends on how you determine the point at which the item needs replacing, what conditions it operates in and what materials it is manufactured from.

A high percentage of leisure sailing boats manufactured in the 1960’s using low cost polyester resins with glass reinforcements are still in service today, over 50 years later, despite being operated in a harsh marine environment exposed to high levels of UV light. Many of these vessels spend their whole life on the water, only being removed once a year to be anti-fouled.

Modern composite materials manufactured from more durable resin systems, such as vinylester or epoxy are now being used for the manufacture of large structures such as bridges with a design life of 100 years or more.

Modern accelerated weather testing equipment is used to verify the degradation in performance of typical laminates used in such structures and this data is used by the engineer to ensure the integrity of the structure even after deterioration of some of its mechanical properties.

Where a product is subject to cyclic loading (such as a wind turbine blade) engineers will use FEA (finite element analysis) to ensure the ability of the laminates to withstand the required number of cycles. 106 cycles is now commonplace.

PE Composites’ extensive materials knowledge helps ensure the correct selection of materials, processing methodologies and the need for any additional protection required for any given product and application.

How is a composite laminate designed?

A composite laminate is anisotropic (has different properties in different directions) and can be manufactured and processed in an almost infinite number of ways. This makes it more complex to engineer than using conventional materials such as metals which are largely isotropic.

Materials data sheets are available for composite materials but these are for specific combinations of materials, processed in a particular manner, thus providing a guide to what might be achieved. This is useful when comparing general properties with other materials, but cannot be relied upon for critical structures.

Fortunately, there are now standard FEA (finite element engineering) software packages available which are compatible with leading 3D CAD packages. This software draws on increasingly large databases of materials properties.

Typically, geometry produced in CAD such as Rhino and AutoCAD, SolidWorks etc. is input into a meshing software package such as HyperMesh and from there into the structural engineering software. There are many packages available but MSC Nastran/Patran is one with a long-standing reputation.

It is important to ensure that composites structural engineering is undertaken by staff which fully understand how composites are manufactured, and which combinations of materials are most likely to produce the most cost-effective product.

PE Composites draw on their extensive experience to quickly determine the most appropriate solution to a viable structure which will satisfy your particular requirements and specifications.

How much will my composite structure weigh when compared to a metal one?

This is the most commonly asked question, and the most difficult to answer generically.

The cost of a composite part is made up of the materials, labour, tooling, moulds, consumables and the associated curing process costs.

The range of costs for any of the above can be very high. e.g. Carbon fibre is very expensive when compared to chopped glass fibre mat, but offers much increased strength and stiffness and hence typically lighter structures. Epoxy resin is 3-5 times more costly than polyester resin, but less will be required and so on.

If a single component is required, then that part will carry 100% of the costs of any tooling required for its manufacture. This might include a master plug and a mould set. However, if 20 components are required, only 5% of the tooling costs need to be added to the cost of each part, making a very substantial difference to the part cost and adding real focus to the proposed method of manufacture to reduce tooling costs.

Hand lay-up components are often cured under atmospheric conditions and thus tooling is low-temperature and low cost, and no oven operating costs are incurred.

High integrity components often manufactured from carbon fibre and needing to achieve the very highest levels of performance are cured in ovens at elevated temperatures. Cure times are often 16 hours and thus the costs attributed to the cure can be high and include a requirement for tooling that will operate at the elevated temperature of the oven as well as the energy costs.

For the above reasons, you will see that providing even a budget estimate without knowing more about the structure is virtually impossible. So, if you have an enquiry that requires a cost estimate, please contact us early during the design phase for advice. We may be able to save you money.

How much will a composite part cost me when compared to a metal one?

This is the most commonly asked question, and the most difficult to answer generically.
The cost of a composite part is made up of the following constituent parts:

Cost of reinforcements

Cost of resin

Cost of core materials

Cost of labour

Cost of tooling and moulds

Cost of consumable materials used during processing (vacuum bags, etc.)

Costs associated with the cure process

CAPEX machine costs

The range of costs for any of the above can be very high. e.g. Carbon fibre is very expensive when compared to chopped glass fibre mat. Epoxy resin is 3-5 times more costly than polyester resin, and so on.

If a single component is required, then that part will carry 100% of the costs of any tooling required for its manufacture. This might include a master plug and a mould set. However, if 20 components are required, only 5% of the tooling costs need to be added to the cost of each part, making a very substantial different to the part cost and adding real focus to the proposed method of manufacture to reduce tooling costs.

Hand lay-up components are often cure under atmospheric conditions and thus tooling is low-temperature and low cost, and no oven operating costs are incurred.

High integrity components often manufactured from carbon fibre and needing to achieve the very highest levels of performance are cured in ovens at elevated temperatures. Cure times are often 16 hours and thus the costs attributed to the cure can be high and include a requirement for tooling that will operate at the elevated temperature of the oven as well as the energy costs.

For the above reasons, you will see that providing even a budget estimate without knowing more about the structure is virtually impossible. So, if you have an enquiry that requires a cost estimate, please contact us early during the design phase for advice. We may be able to save you money.

What end of life options are there for my composite structures? Can they be recycled?

Recycling composite materials is difficult because of the nature of the matrix, but as usage grows more and more companies are researching methods of handling these materials at the end of their life. As the amount of waste grows, the more likely a company will focus on its recycling as a viable business model.

As a result, there are now a number of companies in the UK and elsewhere who offer different methods of treating the waste, other than landfill.

Initially, laminates were mechanically milled into fillers and re-used in other processes, but now it is possible to reclaim the fibres using pyrolysis to dissolve the resin.

Waste can also be incinerated, recovering energy and recycling the ash produced.

Further information is available on request.

Can a composite structure be repaired?

Composite structures have been around for decades and there are already well-established repair methods available. As more advanced structures, such as wind turbine blades, bridges, motor vehicles, etc., are being produced, new methods are being developed especially for each particular structure.

At PE Composites, we repair and refurbish composite structures that are designed for a long service life before placing them back in service for a further period.

When we supply a new structure or assembly we are able to provide a manual providing inspection and repair instructions if required.